fletch3jason

Hello everyone, i just purchased a 93 Miata with a Greddy turbo system on it and was looking for a little advice about it. first off i am a good mechanic but im new to a non turbo car getting a turbo... so from what i have seen so far it looks like the system was hacked together! Someone had used a piece of steel pip for part of the piping to the intake and the pipe was wedged behind the sway bar which wore a hole in the pipe... i removed all the junk work so far and temped it to get the car running. It runs good but still a long way from driving it daily, my question is do i remove the mass air flow sensor and put in a intake temp sensor? and does the computer need to be mapped? i just want to have the car running proper. any help on the subject would be great! thanks Jason

supercooper

Im assuming it still has the stock ECU???

AlexL

Yes, dump your AFM. Get a megasquirt, build your own or order one from the Classifieds here. Read this: https://www.miataturbo.net/useful-sa...asquirt-13676/

fletch3jason

if i swap out the afm/maf don't i also need a map sensor installed as well? and i would think the computer is factory. considering the hack job on the install of the system.

Harv

iTrader: (4)

The stock computer needs the AFM/MAF to make the car work. It cannot work off of a MAP sensor.

The Megasquirt is a fully standalone replacement ECU that can work off a MAP sensor. If you have the Greddy kit on the car then the thing probably has an adjustable fuel pressure regulator (AFPR) on the car to dump more fuel into the system when boost comes on. This works like **** and will blow up the car sooner rather than later. The AFPR is most likely a blue circular thing that is screwed into the firewall of the engine bay. Take it off and throw it away and buy/build a Megasquirt to replace it.

Then throw the whole greddy kit on the classifieds and start over with a real turbo system.

fletch3jason

ok to my understanding aftermarket computers come with an on board MAP sensor, if i remove the afm and install a intake temp sensor that would be wired into the afm wiring. so its not really removing it totally but faking the computer into thinking its still there. and using air temp to change the voltage top add or remove fuel.. like i said up top, i know my way around a car.. and looking more into this i see that running a intercooler means that a temp sensor is needed to comp for the cooler air being forced into the intake. colder air + fuel = more HP..

Harv

iTrader: (4)

If you remove the AFM the stock computer has no idea how much air is in the system and therefore cannot adequately manage the fueling. You can't remove the AFM if you have the stock computer in the car.

If you put the new computer in the car, yes, you then have a MAP sensor and the wiring for the new computer is configured to pull the intake temps off an AIT sensor that you install before the intake manifold and wire into the existing AFM/MAF harness.

Miater

Welcome to the forum.

Please start another thread in the DIY turbo section to ask for help or advise.

Braineack

iTrader: (62)

fletch3jason, congrats on signing up at the best site on the web!

AlexL

So true.

Harv

iTrader: (4)

I so should have listened to this.

supercooper

yup... If i could go back in time, i would slap the previous owner of my car.. The greddy "kit" is poop.

dieselmiata

iTrader: (3)

It's not that bad as long as you replace the downpipe. And manifold. And oil lines. And possibly the turbo.

supercooper

haha THIS^

Very true... ive replaced it all, except the turbo and Feed line to the turbo. (turbo is the next to go)
Oh, and the Heat shield.... i like the heat shield.... lol

Harv

iTrader: (4)

We joke about this so much, but it's so true. I'm down to the oil feed line and the turbo as the only things remaining from the kit.

dieselmiata

iTrader: (3)

I still have the downpipe, but that will be changed before Christmas. Already have different manifold and oil supply/drain lines.

The turbo itself isn't really that bad though. TD04 variants are everywhere and seem to hold up well enough.

Harv

iTrader: (4)

Oh the downpipe is horrible. I swapped that for the turbo tony a while back.